Effect of Process Parameters on Chitosan-mediated Microalgae Flocculation

Abstract

Today, microalgae have received considerable interest as an alternative feedstock for biofuel, animal feed, human food, and pharmaceuticals because they possess valuable oils and biomolecules. The main problem of the cost of microalgae production is generally associated with the harvesting process. Flocculation is an effective method to harvest microalgal biomass and minimize the operating cost. In this study, the effect of the chitosan solution, different pH conditions, and flocculation time on flocculation process of Chlorella minutissima and Nannochloropsis oculata were investigated, and the obtained data were evaluated statistically. Flocculation efficiency of C. minutissima and N. ocula-ta were the highest under the conditions of 10 pH, 100 mg L-1 chitosan concentration, and flocculation time of 60 min, and found as 97 % and 85 %. It was also found that chitosan flocculation could be improved with pH increase. This study showed that chitosan is a favorable flocculant because of its high efficiency, being non-toxic, and enabling the reusability of the growth medium after flocculation.